Output control for radio receiving sets



Jan. 15, 1929. 1,699,028

R. SELIGER OUTPUT CONTROL FOR RADIO RECEIVING SETS Filed Sept. 16. 1924 2 Sheets-Sheet l VIII/1 Jan. 15, 1929. 1,699,028

7 R. SELIGER OUTPUT CONTROL FOR RADIO RECEIVING SETS 7 Filed Sept. 16, 1924 2 Sheets-$11861 2 5 fig;

\ 2d a j /0 m Patented Jan. 15, 1929.

UNITED STATES ROBERT SEI-IGEB, OF PHILADELPHIA, PENNSYLVANIA OUTPUT CONTROL FOR RADIO RECEIVING SETS.

Application filed September 16, 1924. Serial No. 738,071.

This invention relates to new devices for radio receiving sets particularly to a device for controlling the output of the receiving set in a simple and efiicient manner.

,5 An object of the invention resides in providing an output controlling device for radio receiving sets, wherein. a rotatable member mounted on the instrument board of the receiving set is adapted to operate suitablecom tact means interposed in the circuit of the receiving set, of the type wherein a plurality of stages of amplification are used for the.

purpose of interposing the sound reproducing device, in any stage or output circuit of said set, through the operation of said rotatable means for operating the desired con tact means.

Another object of the invention is to provide a pluralityof pairs of normally engaged contact members arranged in predetermined relation era-ole by a suitable manually rotatable means for. cutting out predetermined portions of a radio receiving circuit so that the sound reproducing means of the radio receiving set may be interposed in any predetermined portion'of said receiving circuit.

A still further object of the invention resides in providing a control device for the output of a radio receivin cludes a disc member, suita ly supported in the rear of the instrument panel of the receiving set, in which is rotatably mounteda shaft carrying a pair of operating and contact arms suitably insulated from one another and having circuit connections with the sound reproducing means for said radio set, which forms the output circuit thereof, and which is adapted to operate suitable con- 49 tacts mounted in a predetermined relation on said disc member, in order to cut out predetermined portions of the radio receiving circuit of said set and interpose the sound reproducing means and output circuit of the set in any predetermined ortion of said set, so that the sound repro ucing means may be connected with the detector circuit, or any stage of amplification in the radio receiving set.

50 The invention also comprehends other obj ects and improvements in the details of construction and arrangement of the parts,

- which are more particularly pointed out in the following detailed description and in the claim, directed to a referred form of the invention, it being on erstood, however, that one contact of each pair being opset, which invarious changes in the details of construction and arrangement of the'parts, for carrying out the above objects of the invention in an eflicient manner may bemade, without departing from the spirit and scope of the invention as described and claimed.

In the drawing, forming part of this appllcation:

Figure 1 is a vertical sectional view through a portion of the instrument panel of a radio receiving set equipped with the invention, the invention being applied to said panel and shown in section, portions however being left in elevation.

Figure 2 is a vertical'transverse sectional view, through the improved control device, taken on the line 2-2 of Figure 1.

Figure 3 is a vertical sectlonal view, taken on the line 3-3 of Figure 1,

Figure 4 is a horizontal sectional view, through the control device, taken on the line H of Figure 2.

Figure 5 is a detail enlarged perspective view of one of the operating and contact arms.

Figure 6 is an enlarged detail perspective view of the resilient contact arm of one or";

ghe pairs of the arms mounted on a disc mem- Figure 7 is a wiring diagram or the invention in connection with a radio receiving set, having two stages of amplification, showing the manner of connecting the device, for controlling the circuit to said receiving set.

The instrument panel is indicated at 1, of a radio receiving set of any suitable character, preferably of the multi-tube type havin a detector circuit, and a plurality of ampli ing circuits interconnected in the usual and well known manner, and with which the present invention is designed for use.

A tubular mounting member 2 is positioned in an opening in the panel 1 and receives a nut 3, having threaded connection therewith for securing the bracket member 4 to the rear side of the panel and also for forming a bearing to rotatably mount the operating shaft 5, adjacent one end thereof. A. disc member 6 is mounted on the rear end of the bracket member 4 in any suitable manner, such as is illustrated in Figur 2, and in which is mounted a bearing bushing 7, aligned with the securing member 2, for providing a bearing for the oppositeend of the shaft 5. An insulating s1eeve8 is the arms being secured to said insulating sleeve and held thereon against rotation by suitable set screws 13. A spring 14 is interposed between the bearing bushing 7 in the disc 6, and a washer 15 is positioned on the shaft 5 and abutting the nut 9 adjacent the disc 6, so that the shaft is normally retained in one position for rotation, relative to the panel 1, while an operating .arm 16 of any usual form is mounted on the outer end of .the shaft, projecting beyond the base of the panel 1, and through which the'shaft 5 is adapted to be suitably manually rotated for effecting the control of the radio circuit in a predetermined manner, as will presently appear.

-A pull wheel or contact stud 17 having threaded shanks projecting therefrom are mounted in circumferential relation, .and concentrically with respect to the shafts 5 on the disc 6, each of said sets being arranged diametrically opposite the corresponding set with the opposite side of the shaft 5. There are sufficient of the contact studs 17 to provide a pair of diametrically opposite studs to correspond to each stage of amplification in the radio receiving set, with the exception of the last stage, and which form the terminals for interposing the primaries of the several amplifying transform ers used in circuit. A plurality of resilient contact members are mounted in circumferential relation outwardly of the contact studs 17 as indicated at 18, there being a resilient contact member associated with each contact stud and adapted to normally contact with the same for closing thecircuits controlled thereby. There are also a pair of extra resilient contact members in addition to the ones cooperating with the contact studs as indicated at 18', arranged in concentric relation with respect to the resilient contact members 18, and which control and form the output terminals'for the last stage of amplification for the radio'receiving set, in order that the full power of the set may be applied to a suitable sound reproducing device. The resilient contact members 18 and 18' are of such a construction that the ones located at the right hand side of Figure 2 are adapted for engagement with the outer end of the operatingarm 10, nearest to the .disc'fi, while the contact members at the 0ppositesides of the disc are of a length sufficient to lie in the path of movement of the arm 10, adjacent to the panel. Each of these contact members 18, comprises a resilient strip, having a laterally extending foot 19, adapted to seat against the face of the disc 6, and to be secured thereto by suitable bolts and nuts to which the circuit wires are connected for interposing the contact in the proper circuit while the central portions of the strip 18 are formed with bolt portions 20 adapted to engage the contact studs 17 in a manner as clearly illustrated in the drawing.

It will thus be seen by an examination of Figure 4 that the operating arms 10 simultaneously engage the resilient contact members at diametrically opposed points on the disc 6, for moving the same out of contact with the contact studs 17, with which they usually cooperate for closing the circuit connected therewith. The cross bar 21, preferably formed of suitable insulating material is mounted in the central portion of thebracket 4, below the arm 10, and a pair-of fingers 22, of resilient material are posltioned thereon, so' as to contact with the hub 11,

of the contact arm 10, in order that suitable circuit connection may be made with the securing means 23, mounting said contact fingers on the cross bar 21, for interposing the contact arms in circuit with the sound reproducing means so that they will control the output circuit of the radio receiving set.

From the wiring diagram shown in Fig-- ure 7, it will be seen that the final output circuit of the radio receiving set has its terminals connected to the two resilient contacts 18' by the wires 24, so that when the arms 10 are positioned to engage these contacts 18, the phones or other sound reproducing device, indicated diagrammatically at 25 will be interposed in the output circuit of the radio receiving setfor receiving the full power of said set. The output circuit of the next preceding amplifying circuit of the set and the detector circuit thereof as indicated at 26 and 27 respectively, are connected to corresponding diametrlcall opposite contact members 18, adjacent t e contact members 18 in succession in the direction of rotation in a counter clockwise direction from the contact members 18'. maries of the amplifying transformers 28 and 29 of the second and first stage of amplification of said radio receiving set are connected to the contact studs 17 arranged in diametrically opposite relation to one another by the wires 30 and 31 respectively, in corresponding relation with the connections to the contact members 26' and 27 respectively.

It will be seen that by the proper operation of the operating knob 16, the operating The pri- In this way, it will be seen that the necessity for removing and striking in a plurality of separate and independent plug receptacles, with a phone plug carrying the circuit connections to the sound reproducing means is eliminated, and a substantially simple device', whichmay be readily and manually rotated has been provided for interposing the sound reproducing means in any desired circuit through the rotation of the operating means 16 manually, so as to position suitable scale markings thereon to correspond with markings on the instrument panel, indicating the positioning of the arms 10, in engagement with the resilient contact members of the respective stages of amplification, so that the desired number of tubes may be interposed in the radio receiving circuit for applying the desired amount of power to a received signal for the purpose of amplifying the same before reproduction in the sound reproducing device 25.

. -While the drawings illustrate the preferred form of the invention, it will be readily understood that various embodiments of this construction may be made, wherein contact members are positioned on a plate or disc adapted to be operated in the manner above described by a suitable rotatable member for efl'ecting the interposition of the sound reproducing means in the output circuit of any desired stage of amplification of a radio receiving set of the multi tube type,

without departing from the spirit and scope of the invention as above described.

What is claimed is:

A multiple circuit control mechanism, comprising a support, a plurality of stationary contacts mounted in circumferential relation on said support, a plurality of movable contacts mounted in circumferential relation on said support and normally engaging said stationary contacts, a shaft rotatably mounted in said support, and centered with respect to the concentric relation of said contacts, each of said contacts being disposed in spaced parallel relation with said shafts and with the free ends of the stationary contacts and terminating short of the free ends of the movable contacts, and contact engaging elements mounted in axially alinedrelation on said shaft and projecting radially therefrom operable to selectively disengage the said movable contacts from the stationary contacts.

In testimony whereof I aflix my signature. ROBERT SELIGER. 

